Acknowledgment of Media Waveforms between Telecommunications Endpoints

ABSTRACT

An apparatus and method are disclosed that enable a first telecommunications endpoint to ensure that a second endpoint is receiving the first endpoint&#39;s packet stream transmissions with a satisfactory waveform quality. When the second endpoint receives the packet stream, it decodes the media waveform from the stream, encodes the waveform back into a second packet stream, and transmits some or all of the packets in the second stream back to the first endpoint. The first endpoint then decodes the received waveform in the second stream and compares it to the original waveform transmitted to the second endpoint. Based on the comparison, the first endpoint adjusts the value of a quality indication, and provides the quality indication to its user and to the second endpoint. Advantageously, the user at the second endpoint is able to determine whether the received waveform is, in fact, close enough to the waveform that the first endpoint&#39;s user intended to be received and understood.

FIELD OF THE INVENTION

The present invention relates to telecommunications in general, and,more particularly, to verifying whether a media waveform that is encodedby a first telecommunications endpoint has been satisfactorily receivedby a second telecommunications endpoint.

BACKGROUND OF THE INVENTION

When people communicate with each other over a distance, there is oftenuncertainty as to whether the participants hear each other. Theuncertainty can be attributed to noise or other forms of impairment thatare present in the transmission path between the participants. In radiocommunication, for example, impairments can come in the form ofco-channel interference, Rayleigh fading, thermal noise, and so forth.Even in landline communications, in which a radio link is not present,impairments can still come in the form of echoes, transcoding errors,packet losses, and so forth.

The uncertainty in achieving successful communication is not specific toany one form of communication. This is evident, for example, in two-wayradio communication for military, aerospace, or public service purposes,in which the participants are often forced to repeat what was heard.Additionally, in order to acknowledge and confirm the accuracy of thecommunication explicitly, the participants often have to use words suchas “roger” to indicate that information has been received or “copy” toindicate that what was just said is understood. Even in cellulartelecommunications, which comprises an adapted form of two-way radiocommunication, commercials and advertisements by the cellular serviceproviders often feature themes of anxiety caused by a cell phone usernot hearing someone else or of a service rep continually asking ifsomeone else is able to hear him on his cell phone.

Not surprisingly, a lot of effort has been spent on improving therobustness of communications and ensuring each participant in aconversation that the other person is, in fact, hearing him. In a Voiceover Internet Protocol context, for example, protocols such as Real-timeTransport Control Protocol (RTCP) have been developed to deal withimproving the robustness of communication, among other things. RTCP inparticular provides out-of-band control information for a Real-timeTransport Protocol (RTP) packet stream that conveys voice or other mediainformation between endpoints. RTCP is intended to be used to transmitcontrol packets periodically to participants in a streaming multimediasession, such as that transacted during a VoIP call. The primaryfunction of RTCP is to provide feedback on the quality of service thatis being provided for the transmitted RTP packet stream. The receivingendpoint of a packet stream can transmit RTCP packets back to thetransmitting endpoint, in order to report the quality of service beingexperienced by the receiving endpoint.

SUMMARY OF THE INVENTION

The problem with relying on some of the protocols in the prior art, suchas RTCP, is that they are primarily concerned with providing feedback onthe quality of service, which concerns the properties of bandwidth,error rate, and latency, and which characterizes how well an endpoint isreceiving data packets and bits. However, RTCP does not provide amechanism for reporting on signal quality that is measured in the analogdomain, which has to do with the relatively new concept of mediawaveform quality.

Media waveform quality is concerned with, but is not limited to, theproperties of loudness, audio distortion, noise, fading, crosstalk,echo, and video distortion. In other words, waveform quality isconcerned with different signal properties than is quality of service.For example, a receiving endpoint might be receiving packets at anacceptable quality of service, but might be receiving the underlyingmedia waveform at an unacceptable waveform quality, on account of animpairment being introduced in the analog domain. One such analog-domainimpairment is that which is introduced by a speech transcoderimperfectly converting speech signals from one format to another.

Moreover, even if the receiving endpoint, or more specifically its user,is receiving the media waveform with an acceptable perceived waveformquality, the recipient might not be able to determine that the receivedand decoded waveform still differs significantly from the waveform thatwas encoded and transmitted. This can be critical, for example, whentransmitting high-quality audio for evaluation purposes or in systemsthat are used to memorialize conversations for legal purposes. That is,not only is it critical to receive acceptable waveform quality asperceived by the receiving party, it is often critical to receive whatthe transmitting party intended that the receiving party hear andunderstand.

The present invention enables a first telecommunications endpoint toensure that a second endpoint is receiving the first endpoint's packetstream transmissions with a satisfactory waveform quality. In accordancewith the illustrative embodiment of the present invention, when thesecond endpoint receives the packet stream, it decodes the mediawaveform from the stream, encodes the waveform back into a second packetstream, and transmits some or all of the packets in the second streamback to the first endpoint. The first endpoint then decodes the receivedwaveform in the second stream and compares it to the original waveformtransmitted to the second endpoint. Based on the comparison, the firstendpoint adjusts the value of a quality indication, presents status thatis based on the quality indication to its user, and transmits thequality indication to the second endpoint. In doing so, the user at thesecond endpoint is able to determine whether the received waveform is,in fact, close enough to the waveform that the first endpoint's userintended to be received and understood.

The invention is based on the idea that if the round-trip quality (i.e.,that associated with going from first endpoint to second endpoint andback) is adequate, then the one-way-trip quality (i.e., that associatedwith going from first endpoint to second endpoint only) must be adequateas well. In accordance with the illustrative embodiment, the same ideais simultaneously applied in the opposite direction as well, in whichthe second endpoint compares a waveform that it receives from the firstendpoint with the original waveform that the second endpoint transmittedto the first.

The endpoint of the illustrative embodiment of the present inventioncomprises: a transmitter interface that transmits, to a secondtelecommunications endpoint, a first packet stream that conveys a firstmedia waveform a(t); a receiver interface that receives, from the secondtelecommunications endpoint, a second packet stream of data thatrepresent a second media waveform a′(t); a processor that compares a′(t)with a(t) according to a predetermined characteristic and, based on thecomparison, adjusts the value of a first quality indication; and a userinterface that presents status that is based on the value of the firstquality indication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a block diagram of the salient components oftelecommunications system 100, in accordance with the illustrativeembodiment of the present invention.

FIG. 2 is a block diagram of the salient components oftelecommunications endpoint 101-m within system 100.

FIG. 3 depicts a diagram of the salient messages and tasks that arerelated to exchanging packet streams, as well as to analyzing thewaveform content of those packet streams, in accordance with theillustrative embodiment of the present invention.

FIG. 4 depicts a diagram of salient messages and tasks depicted in FIG.3, in which endpoints 101-1 and 101-2 have exchanged roles.

FIG. 5 depicts another block diagram of telecommunications system 100,showing the presence of speech transcoders within network 102.

DETAILED DESCRIPTION

FIG. 1 depicts a block diagram of the salient components oftelecommunications system 100, in accordance with the illustrativeembodiment of the present invention. System 100 comprisestelecommunications endpoints 101-1 through 101-4 and telecommunicationstransmission network 102, interconnected as shown. Although theillustrative embodiment comprises four telecommunications endpoints, itwill be clear to those skilled in the art, after reading thisdisclosure, how to make and use alternative embodiments of the presentinvention that comprise any number of telecommunications endpoints.

Telecommunications endpoint 101-m, where m has a value between 1 and M(M being equal to four in the illustrative embodiment) is a device thatis capable of originating and/or receiving packet streams that areexchanged during calls. For example, endpoint 101-m can be a desksettelephone, a cellular telephone, a notebook computer, a personal digitalassistant (PDA), a conference bridge, and so forth. Some or all ofendpoints 101-1 through 101-M can be identical to or different from oneanother; for example, endpoint 101-1 can be a deskset, endpoint 101-2can be a cell phone, endpoint 101-3 can be a softphone on a notebookcomputer, and endpoint 101-4 can be a conference bridge.

Endpoint 101-m handles calls via telecommunications transmission network102 and is capable of exchanging voice and call processing-relatedsignals with one or more other devices, such as the other endpointswithin system 100. To this end, endpoint 101-m exchanges InternetProtocol (IP) data packets with other devices. In some alternativeembodiments, however, endpoint 101-m might be an analog device that doesnot digitize information prior to transmission. In any event, it will beclear to those skilled in the art, after reading this specification, howto make and use telecommunications endpoint 101-m.

Telecommunications transmission network 102 is a network that transportsthe packet streams associated with calls between two or moretelecommunications endpoints. A packet stream can comprise voice, video,and so forth. In accordance with the illustrative embodiment, network102 comprises packet-switched infrastructure. However, it will be clearto those skilled in the art, after reading this disclosure, how to makeand use alternative embodiments of the present invention in whichnetwork 102 comprises:

i. the Public Switched Telephone Network, or

ii. the Internet, or

iii. one or more other telecommunications networks, or

iv. any combination of i, ii, and iii.

Furthermore, as those who are skilled in the art will appreciate,network 102 can comprise speech transcoders or other types oftranscoders, as are known in the art, in order to convert from one typeof packet stream representation to another.

FIG. 2 is a block diagram of the salient components oftelecommunications endpoint 101-m in accordance with the illustrativeembodiment of the present invention, which components are interconnectedas shown. In accordance with the illustrative embodiment,telecommunications endpoint 101-m comprises:

i. receiver interface 201,

ii. transmitter interface 202,

iii. processor 203,

iv. memory 204,

v. display 205,

vi. loudspeaker 206, and

vii. vibration mechanism 207.

It will be clear to those skilled in the art, after reading thisdisclosure, how to make and use alternative embodiments of the presentinvention in which telecommunications endpoint 101-m comprises anysubcombination of the components listed above.

Receiver interface 201 and transmitter interface 202 comprise thecircuitry that enables endpoint 101-m to respectively receive signalsfrom and transmit signals to network 102, in well-known fashion. Inaccordance with the illustrative embodiment, endpoint 101-m receives andtransmits media waveform signals that are encoded via the ITU G.729standard and represented in Voice over Internet Protocol (VoIP) packetstreams of data, in well-known fashion. As those who are skilled in theart will appreciate, in some alternative embodiments endpoint 101-mreceives and transmits media waveform signals that are encoded and/orrepresented in a different format.

Processor 203 is a general-purpose processor that is capable ofreceiving information from receive interface 201, of executinginstructions stored in memory 204, of reading data from and writing datainto memory 204, and of transmitting information to transmit interface202. Additionally, processor 203 is able to provide signals to display205, loudspeaker 206, and vibration mechanism 207. In some alternativeembodiments of the present invention, processor 203 might be aspecial-purpose processor.

Memory 204 stores the instructions and data used by processor 203, inwell-known fashion. Memory 204 can be any combination of dynamicrandom-access memory (RAM), flash memory, disk drive memory, and soforth.

Display 205 is part of the user interface of endpoint 101-m. Inaccordance with the illustrative embodiment, display 205 comprises aliquid crystal display that is able to present the endpoint's user witha visual representation of status. It will be clear to those skilled inthe art how to make and use alternative embodiments of the presentinvention in which display 205 comprises other than a liquid crystaldisplay.

Loudspeaker 206 is another part of the user interface of endpoint 101-m.In accordance with the illustrative embodiment, loudspeaker 206 is ableto present the endpoint's user with an audible representation of status.As those who are skilled in the art will appreciate, in some alternativeembodiments of endpoint 101-m, loudspeaker 206 can instead be a type ofelectro-acoustic transducer other than a loudspeaker, such as anearpiece. In any event, it will be clear to those skilled on the art howto make and use loudspeaker 206.

Vibration mechanism 207 is yet another part of the user interface ofendpoint 101-m. In accordance with the illustrative embodiment,mechanism 207 is able to present the endpoint's user with a tactilerepresentation of status. It will be clear to those skilled on the arthow to make and use vibration mechanism 207.

In accordance with the illustrative embodiment, endpoint 101-m performsthe tasks described below and with respect to FIGS. 3 and 4. As thosewho are skilled in the art will appreciate, each component withinendpoint 101-m can perform a different subset of the described tasks.For example, those tasks that processor 203 can perform include thedecoding of a media waveform from a received packet stream, the encodingof a media waveform into a packet stream to be transmitted, and thecomparing of one or more predetermined characteristics of a first mediawaveform with those of a second media waveform.

FIG. 3 depicts a diagram of the salient messages and tasks that arerelated to exchanging packet streams, as well as to analyzing thewaveform content of those packet streams, in accordance with theillustrative embodiment of the present invention. As those who areskilled in the art will appreciate, some of the messages and tasks thatappear in the diagrams that follow can be performed in parallel or in adifferent order than that depicted. Moreover, those who are skilled inthe art will further appreciate that in some alternative embodiments ofthe present invention, only a subset of the depicted messages and tasksare performed.

As depicted in FIG. 3, telecommunications endpoints 101-1 and 101-2 areexchanging packet streams of data, each of which represents a mediawaveform, as part of a two-way call with each other. In accordance withthe scenario, endpoints 101-1 and 101-2 exchange voice waveforms oftheir user's voices. However, as those who are skilled in the art willappreciate, in other scenarios, two or more endpoints can exchange othertypes of media, in accordance with the techniques described herein.

Endpoint 101-1 transmits packet stream 301 to endpoint 101-2, whichpacket stream of data conveys a first media waveform a(t), which is ofthe voice of endpoint 101-1's user.

Endpoint 101-2 receives packet stream 301 and, at task 302, decodes asecond media waveform a′(t) from the received packet stream. Thedistinction between the first media waveform and the second mediawaveform is important, in that the second media waveform is supposed tobe a reproduction of the first media waveform, but is not necessarilyguaranteed to be an exact reproduction. The lack of a guarantee is dueto the first media waveform being subjected to one or more impairments(e.g., encoding errors, transcoding errors, decoding errors, etc.)between endpoint 101-1 and endpoint 101-2.

Endpoint 101-2, at task 303, then encodes the decoded second mediawaveform into a second packet stream of data, namely packet stream 304,and transmits the packet stream to endpoint 101-1. This is performed sothat endpoint 101-1 will have a waveform to compare with the first mediawaveform that it previously transmitted to endpoint 101-2.

In some alternative embodiments, endpoint 101-2 prepares and transmits arepresentative model of the waveform, instead of encoding andtransmitting the waveform itself. In some other alternative embodiments,endpoint 101-2 selects some or all of the payload data received inpacket stream 301 and inserts the payload data into packet stream 304,instead of decoding and encoding that data.

Endpoint 101-1 receives packet stream 304 and decodes a third mediawaveform from the received packet stream. The distinction between thefirst media waveform and the third media waveform, or between the secondmedia waveform and the third media waveform, is important in that thethird media waveform is supposed to be a reproduction of the first mediawaveform—or of the second media waveform, for that matter—but is notnecessarily guaranteed to be an exact reproduction.

At task 305, after decoding the signal, endpoint 101-1 compares a thefirst media waveform, which was represented by a portion of packetstream 301, with the third media waveform, which was represented by aportion of packet stream 304, based on a predetermined characteristic orcharacteristics. The characteristics used in the comparison can compriseone or more of the following:

i. loudness,

ii. audio distortion,

iii. noise,

iv. fading,

v. crosstalk,

vi. echo, and

vii. video distortion (e.g., spatial, temporal, optical, etc.).

As those who are skilled in the art will appreciate, more than onecharacteristic can be compared and other characteristics not listedabove can be compared. Furthermore, the actual method of comparison caninvolve a correlation, a bit-by-bit matching, an evaluation of thetransmitted waveform with respect to a received speech or music modelthat represents the waveform, and so forth. In any event, it will beclear to those skilled in the art how to compare one waveform to anotherwaveform or to a representation (e.g., a model, etc.) of that otherwaveform, based on one or more characteristics.

Based on the outcome of the comparison performed at task 305, endpoint101-1 adjusts the value of a quality indication and subsequentlytransmits it to endpoint 101-2 as part of message 306. For example, anindication of acceptable quality can be transmitted whenever the twowaveforms compare acceptably enough. This might be dictated by thepossibility that any waveform degradation might have occurred during thetransmission of stream 304, not during the transmission of stream 301,in which case only a positive indication of acceptable quality willprovide a definitive statement of the waveform quality experienced byendpoint 101-2.

Alternatively, an indication of unacceptable quality can be transmittedwhenever the two waveforms fail to compare unacceptably. This might beappropriate when, for example, when the media waveform represented bystream 304 is guaranteed not to have suffered degradation, such as whenstream 304 is transmitted over a conditioned path with losslessencoding. In any event, it will be clear to those skilled in the art howto determine a threshold of acceptability, based on the characteristicor characteristics used in the comparison.

At task 307, endpoint 101-1 presents to its user the status of thewaveform transmission, via the user interface (i.e., display 205,loudspeaker 206, and/or vibration mechanism 207 of endpoint 101-1). Thestatus is based on the quality indication whose value was adjusted attask 305.

The method of presentation to endpoint 101-1's user (e.g., visual,audible, tactile, etc.), in some embodiments, depends on the value ofthe quality indication as adjusted at task 305. Furthermore, in someother embodiments, the method of presentation to the user depends on theaudio mode in which the user operates endpoint 101-1 (e.g., with ahandset, with a headset, with a speaker, etc.). For example, if the useroperates endpoint 101-1 using an audio mode in which the endpoint isheld close to the ear, it might be more effective to provide a tactilesensation to the user for the purpose of providing the quality status.As those who are skilled in the art will appreciate, the presentationmethod can be based on a combination of the quality indication value,the audio mode, and other characteristics of endpoint 101-1, the user,the call, and/or the information exchanged between endpoints.

If the presentation method is visual, display 205 can render the valueof the quality indication in one or more of a variety of formats, suchas by using different numbers, different colors, different numbers ofbars, smiley face/frowning face icons, and so forth.

At task 308 endpoint 101-2 presents to its user the status of thewaveform transmission, via the user interface (i.e., display 205 and/orloudspeaker 206 of endpoint 101-2). The status is based on the qualityindication whose value was provided in message 306.

The method of presentation to endpoint 101-2's user (e.g., visual,audible, tactile, etc.), in some embodiments, depends on the value ofthe quality indication as provided in message 306. Furthermore, in someother embodiments the method of presentation to the user depends on theaudio mode in which the user operates endpoint 101-2. As those who areskilled in the art will appreciate, the presentation method can be basedon a combination of the quality indication value, the audio mode, andother characteristics of endpoint 101-2, the user, the call, and/or theinformation exchanged between endpoints.

In some embodiments, endpoint 101-1 adjusts the number of bitstransmitted per unit time in packet stream 301 going forward, based onthe value of the quality indication determined at task 305. For example,if the quality comparison appears to be favorable, the number of bitstransmitted to endpoint 101-2 might be decreased with little or noeffect in waveform quality—for example, by changing the speech encoding(i.e., vocoding) process. As those who are skilled in the art willappreciate, the decision to increase or decrease the number of bitstransmitted, as well as by how much, can depend on other factors aswell.

In some embodiments, endpoint 101-2 adjusts the number of bitstransmitted per unit time in packet stream 304 going forward, based onthe value of the quality indication received in message 306. Forexample, if the quality comparison appears to be favorable, the numberof bits transmitted back to endpoint 101-1 might be decreased withlittle or no effect in the comparison. As those who are skilled in theart will appreciate, the decision to increase or decrease the number ofbits transmitted, as well as by how much, can depend on other factors aswell.

Throughout the duration of the call, endpoints 101-1 and 101-2continually perform the tasks and exchange the messages described withrespect to FIG. 3. Furthermore, in some embodiments, endpoints 101-1 and101-2 perform each other's roles for a different set of waveforms. Forexample, endpoint 101-2 transmits a media waveform b(t) of its user'svoice to endpoint 101-1, which decodes a media waveform b′(t) from thereceived packet stream. In other words, as depicted in FIG. 4, endpoint101-1 performs the tasks that were performed by endpoint 101-2 in FIG.3, and endpoint 101-2 performs the tasks that were performed by endpoint101-1 in FIG. 3. This reflected by stream 401 being transmitted byendpoint 101-2, task 402 being performed by endpoint 101-1, and soforth, where tasks 401 through 408 correspond to tasks 301 through 308,respectively.

As those who are skilled in the art will appreciate, after reading thisspecification, the telecommunications endpoint of the illustrativeembodiment can exchange packet streams, as well as analyze the waveformcontent of those packet streams, as part of a three-way call. In athree-way call (e.g., involving endpoints 101-1, 101-2, and 101-3,etc.), at least one endpoint, such as endpoint 101-1, exchanges packetstreams with two other endpoints, such as endpoints 101-2 and 101-3. Inthat case, endpoint 101-1 would perform the techniques of theillustrative embodiment both on the packet streams associated withendpoint 101-2, as described earlier, and on the packet streamsassociated with endpoint 101-3.

FIG. 5 depicts another block diagram of telecommunications system 100,showing the presence of speech transcoders within network 102. Asdepicted in FIGS. 3 and 4, endpoints 101-1 and 101-2 are communicatingwith each other. The packet streams that are being exchanged traversenetwork 102 elements, including speech transcoders 501-1 and 501-2 andinfrastructures 502-1, 502-2, and 502-3. As those who are skilled in theart will appreciate, the speech transcoders can be situated at gatewaynodes, as are known in the art. Additionally, one or more of thetelecommunications devices depicted (e.g., endpoints, speech encoders,etc.) are able to transmit quality indications to data-processing device503, which can be a server or other device that can be used toconcentrate data and/or control one or more telecommunications devices.

In accordance with the illustrative embodiment, one or more of thedepicted pairs of telecommunications devices (e.g., endpoint 101-1 andtranscoder 501-1, transcoders 501-1 and 501-2, transcoder 501-2 andendpoint 101-2, etc.) are able to perform the tasks described above andwith respect to FIGS. 3 and 4. For example, transcoders 501-1 and 501-2are able to exchange packet streams with each other, compare the contentof those streams, and adjust quality indications accordingly for theirparticular transmission-path segment.

Additionally, one or more of the depicted telecommunications devices areable to transmit their quality indications to data-processing device503. In some embodiments, device 503 is able to transmit messages to oneor more of the devices, in order to modify the packet streams that areexchanged between the devices. For example, if device 503 determinesthat a lower encoding rate might be sufficient along one or moretransmission-path segments between endpoints 101-1 and 101-2, the servermight specify that the affected devices use a vocoder with a lower bitrate. As another example, if device 503 determines that too muchbandwidth is being used to transmit a packet stream back to a device forcomparison purposes, the server might specify that a representation witha lower bit rate be used to represent a waveform, such as arepresentative speech model.

As those who are skilled in the art will appreciate, after reading thisspecification, endpoint 101-m or device 503 might be a centralizeddata-processing system, such as a conference bridge, which handles theexchange of packet streams with at least two other endpoints, as well asthe analysis of the waveform content of those packet streams and/or thesubsequent notification and control of one or more other devices.

It is to be understood that the disclosure teaches just one example ofthe illustrative embodiment and that many variations of the inventioncan easily be devised by those skilled in the art after reading thisdisclosure and that the scope of the present invention is to bedetermined by the following claims.

1. A first telecommunications endpoint comprising: a transmitterinterface that transmits, to a second telecommunications endpoint, afirst packet stream that conveys a first media waveform a(t); a receiverinterface that receives, from the second telecommunications endpoint, asecond packet stream of data that represent a second media waveforma′(t); a processor that compares a′(t) with a(t) according to apredetermined characteristic and, based on the comparison, adjusts thevalue of a first quality indication; and a user interface that presentsstatus that is based on the value of the first quality indication. 2.The first telecommunications endpoint of claim 1 wherein the transmitterinterface also transmits the first quality indication to the secondtelecommunications endpoint.
 3. The first telecommunications endpoint ofclaim 1 wherein the receiver interface also receives, from the secondtelecommunications endpoint, a third packet stream that conveys a thirdmedia waveform b(t) which has been encoded by the secondtelecommunications endpoint, and wherein the processor decodes a fourthmedia waveform b′(t) from the third packet stream of data and encodesb′(t) into a fourth packet stream of data, and wherein the transmitterinterface also transmits, to the second telecommunications endpoint, thefourth packet stream of data.
 4. The first telecommunications endpointof claim 3 wherein the receiver interface also receives a second qualityindication from the second telecommunications endpoint, wherein thevalue of the second quality indication is based on a comparison betweenb′(t) and b(t).
 5. The first telecommunications endpoint of claim 4wherein the user interface also presents status that is based on thevalue of the second quality indication.
 6. The first telecommunicationsendpoint of claim 1 wherein the first media waveform a(t) is of a user'svoice, and wherein the second media waveform a′(t) is a reproduction ofthe user's voice.
 7. The first telecommunications endpoint of claim 6wherein the number of bits transmitted per unit time in the first packetstream of data is based on the value of the first quality indication. 8.The first telecommunications endpoint of claim 6 wherein the firstpacket stream passes through a speech transcoder that is physicallydiscrete from both the first and second telecommunications endpoints. 9.A first telecommunications endpoint comprising: a processor that decodesa second media waveform a′(t) from a first packet stream that conveys afirst media waveform a(t) and encodes a′(t) into a second packet stream;a transmitter interface that transmits the second packet stream to asecond telecommunications endpoint; a receiver interface that receives,from the second telecommunications endpoint, i) the first packet stream,and ii) a first quality indication, the value of which being based on acomparison of a(t) with a′(t) as decoded from the second packet streamby the second telecommunications endpoint; and a user interface thatpresents status that is based on the value of the first qualityindication.
 10. The first telecommunications endpoint of claim 9 whereinthe number of bits transmitted per unit time in the second packet streamis based on the value of the first quality indication.
 11. The firsttelecommunications endpoint of claim 9 wherein the transmitter interfacealso transmits, to the second telecommunications endpoint, i) a thirdpacket stream of data that conveys a third media waveform b(t), and ii)a second quality indication; and wherein the receiver interface alsoreceives, from the second telecommunications endpoint, a fourth packetstream of data that represent a fourth media waveform b′(t); and whereinthe processor also compares b′(t) with b(t) according to a predeterminedcharacteristic and, based on the comparison, adjusts the value of thesecond quality indication prior to its transmission.
 12. The firsttelecommunications endpoint of claim 11 wherein the user interface alsopresents status that is based on the value of the second qualityindication.
 13. The first telecommunications endpoint of claim 1 whereinthe first media waveform a(t) is of a first user's voice, the secondmedia waveform a′(t) is a reproduction of the first user's voice, thethird media waveform b(t) is of a second user's voice, and the fourthmedia waveform b′(t) is a reproduction of the second user's voice. 14.The first telecommunications endpoint of claim 13 wherein the firstpacket stream passes through a speech transcoder that is physicallydiscrete from both the first and second telecommunications endpoints.15. A telecommunications system comprising: a first telecommunicationsdevice that i) transmits a) a first packet stream to a secondtelecommunications device, the first packet stream conveying a firstmedia waveform a(t), and b) a first quality indication, ii) receives,from the second telecommunications device, a second packet stream ofdata that represent a second media waveform a′(t), and iii) comparesa′(t) with a(t) according to a predetermined characteristic and, basedon the comparison, adjusts the value of the first quality indicationprior to its transmission; and a server that receives the first qualityindication, the server being physically discrete from both the first andsecond telecommunications devices.
 16. The telecommunications system ofclaim 15 wherein the server transmits, based on the value of the firstquality indication, a message to the first telecommunications device tomodify how it encodes a(t) into the first packet stream.
 17. Atelecommunications system of claim 15, further comprising the secondtelecommunications device, wherein the second telecommunications devicei) transmits a) a third packet stream that conveys a third mediawaveform b(t) and b) a second quality indication, ii) receives a fourthpacket stream of data that represent a fourth media waveform b′(t), andiii) compares b′(t) with b(t) according to the predeterminedcharacteristic and, based on the comparison, adjusts the value of thesecond quality indication prior to its transmission; and wherein thefirst telecommunications device also i) receives the third packetstream, and ii) transmits the fourth packet stream; and wherein theserver also receives the second quality indication.
 18. The firsttelecommunications endpoint of claim 17 wherein the first media waveforma(t) is of a first user's voice, the second media waveform a′(t) is areproduction of the first user's voice, the third media waveform b(t) isof a second user's voice, and the fourth media waveform b′(t) is areproduction of the second user's voice.
 19. The telecommunicationssystem of claim 18 wherein the server transmits, based on the value ofthe second quality indication, a message to the secondtelecommunications device to modify how it encodes b(t) into the thirdpacket stream.
 20. The telecommunications system of claim 15 wherein thefirst telecommunications device comprises a speech transcoder.